Michael Lohan and Lindsay LohanLindsay Lohan was reportedly shocked and upset when she heard that her father, Michael Lohan, signed up for the latest season of 'Celebrity Rehab.'

TMZ reports that Lindsay told her friends that she was worried her father would embarrass the family on the show.

It is also reported that Michael never gave a heads-up to Lindsay, of his decision to do 'Rehab,' which upset the 24-year-old actress.

RadarOnline.com reports that Michael checked into 'Celebrity Rehab' to be treated for anger management issues and not for an addiction.

A source told Radar, "Michael is absolutely 100 percent sober. He hasn't been using drugs or alcohol, but he is being treated for anger management issues. Michael has tremendous admiration for Dr. Drew, and was given this opportunity to better himself, and he took it."